TK-22 carbs

I recently picked up an 81 kz 550.

When I first picked it up it would crackle like crazy every time you let off of the throttle. Upon pulling the plugs it appeared it was running very rich. After inspecting the air mixture screws on the carbs they were about 1/4 turn from seated (makes sense why it was running rich).

After setting them to approximately 1-3/8's turn out it appeared to run quite a bit better, crackling 1-2 after letting off of WOT.

Most of my previous carb work has been with restoring old chainsaws or those found on vehicles (pre-78). I haven't worked with a mechanical slide carb before.

1.) After reading up on the TK-22's it appears that I should have an idle advancement when i'm at full choke. This doesn't appear to be happening. It starts up fine on choke but wants to return to the normal idle.

2.) I was thinking about slightly richening the mixture by 1/8-1/4 of a turn as the plugs were slightly more white than I'd want but wasn't sure if I was over reacting as they've had about 1-200 miles on them and they already seem to have some carbon build up around the base.

Anyways, I'm mostly just spitballing before I find time to take them off and give them a good cleaning.

Joshua

The air suction system can also introduce air into the exhaust which can cause some backfiring. Make sure there are no leaks with that system.

If you follow the links in my sig, you will find a link to a bunch of manuals. Get all of them.

There is also a link to the TK22 website which has a link on how to modify the fast-idle setting for choke operation.

(That mod doesn't necessarily increase the RPMs, though it can, but it opens the throttle more to keep the motor running. The idle speed is naturally lower when cold, so this mod helps maintain idle until it warms up. )

If your crackling is not from air leaks in the air-suction system, then the first thing is to see if you have a vacuum leak.